We have observed that the degree of binding of radio-labeled penicillin to N. gonorrhoeae is inversely proportional to the susceptibility of the organism to the antibiotic. Five binding sites have been isolated from the cytoplasmic membrane, the site of the binding. We have observed that so-called "glucose-negative" strains of the gonococcus (tested on routinely-used media) are not negative at all, but by changes in various components of the media, the negative strains exhibit the ability to oxidize the glucose. We have continued our studies on types of the gonococcus and have been able to transform genetically various characteristics. Further, so-called "types" are readily interchangeable by changes in growth media. BIBLIOGRAPHIC REFERENCES: Rodriquez, W. A.K. Saz - 1975. Possible mechanism of decreased susceptibility of Neisseria gonorrhoeae to penicillin. Antimicrob. Ag. and Chemotherap. 8, 788-792. Baron, E. & A.K. Saz - 1976. The effect of types of media on the production of acid from glucose by so-called "glucose-negative" strains of Neisseria gonorrhoeae. J. Clin. Microbial - in press.